This was because the basic-head-subject phrase was not allowing slashed non-head daughters. Relaxing this constraint requires instead constraining subject-head, so that there isn’t ambiguity in sentences like (2):

Perhaps the ambiguity would be desirable, if there is a subtle information-structural difference, perhaps correlating with some intonation difference.

This is what I thought too, but @ebenderis pointing out that it is the information structure library which should provide this coverage, not me. BUT, the information structure library does not in fact support free word order! So… Perhaps that’s it, that’s the support?

I am wondering if, ultimately, fronting generally should be covered by the info-structure library, while the question semantics is additional and is not part of the fronting rule.

It never looked to me like the additional filler-gap rules which I added for the constituent questions library will play nicely with the additional filler-gap rules which the information structure library adds. But I couldn’t quite figure out the relationship between them. The infostructure library uses L-PERIPH feature heavily and I think that it may be precluding sentence embedding that way (not 100% sure at this point). But other than that, it always seemed to me that there may be duplicate work that I am doing here, with the filler-gap rules to cover question-specific fronting.

Or maybe not, because focus may be sentence-final in fronting languages. I remember @sanghoun saying that it may make sense to say that questions are contrastively focused, but I that doesn’t quite match my understanding of what contrastive focus is? Or perhaps we just need a more general definition: a type of focused position which is used for e.g. contrastive and question-related focus. Then something like Russian can be modeled:

Focus is sentence-final, but we don’t know what to do with free word orders, so, we are not modeling that anyway.

Contrastive-focus is sentence-initial, and we add a particle that marks it. Again, because we do not know yet what to do with free word order, the information structure library won’t add much at this point.

Question-related focus is like contrastive focus (and also uses a particle! a different one but still).

Item 3 is covered currently by my analyses for questions, and I suspect that the analysis I added might also cover item 2. I could rename the wh-ques rule to not mention wh, and I could move the rule in the info-structure library, and leave everything else as is. Then item 1 remains unimplemented for free wo for now, but we will have 3 and possibly also 2. How is that for a plan? It will require some additional testing with non-free word orders of course.

To add to the above, I am currently not clear on what the MRS would look like, in terms of its ICONS, for, say, the two possible readings of sentence (2), one with focus on the determiner and one with focus on the whole NP.

(1) I think in this case ambiguity is better than undergeneration.
(2) I don’t think you want the wh head-filler rule and the non-wh one being the same rule, unless the pattern really is identical AND you do something else to correlate [ SF ques ] with the presence of the wh word
(3) Focus on just the determiner v. the whole NP is vexed given current assumptions, because determiners don’t have their own ARG0.

So clearly the string is possible. As for what’s going on in the information structure — that requires a way to differentiate the information structural meaning of (5) compared to say (6) (assuming (6) is grammatical):